摘要
为了降低低码率视频编码算法的块效应与环效应，提出了一种基于自适应分区余弦变换／子波变换和重叠运动补偿的视频编码算法。首先给出一种空－时相关自适应运动估计算法，有效降低运算复杂性；然后通过分层游动窗块区域形成算法检测出帧间预测误差场的高能量区域，对大区域进行子波变换和量化，对零散区域进行余弦变换和量化；根据人类视觉系统（ＨＶＳ）的空－频和时－频特性，给出基于ＨＶＳ的量化模型，以期在信噪比约束下获得最好的主观测试质量．模拟结果表明，对于ＣＩＦ格式图像，在低码率和甚低码率下仍能得到满意的图像质量；算法向下兼容ＩＴＵ的Ｈ．２６３标准，并可以应用于低码率视频会议系统中．
A novel video coding algorithm based on adaptive blocking regional wavelet transform and dis-crete cosine transform is described in this paper. An adaptive algorithm of motion estimation employs the spatial-temproal correlation presented in motion vector field to reduce calculating complexity. The high energy regions ofinterframe predicted difference are first detected using hierarchical sliding-window region forming algorithm.Thedetected regions are segmented to DWT regions and DCY regions. This scheme reduce the ringing-effects andblocking-effects compared with traditional DWT or DCf coding algorithms . A quantization model based on HVSspatiality-frequency and time-frequency feature is used in coding algorithm.Simulation result shows acceptableimage quality for CIF resolution at low bit-rate and very low bit-rate. This video coding algorithm is downwardcompatible with H.263,and is suited for low bit-rate video conference application.
出处
《电子学报》
EI
CAS
CSCD
北大核心
1998年第4期7-11,共5页
Acta Electronica Sinica
关键词
视频编码
子波变换
代码率
图象信号处理
Video coding ,Wavelet transform,Diserete cosine transform,Quantization,Low bit-rate
